Method of manufacturing electric contact plugs



May 29. 1928. I 1571,50

B. MONTEIL METHOP OF MANUFACTURING ELECTRIC CONTACT PLUGS Fild Dec. 22,1925 Patented May 29, 1928.

UNITED. STATES PATENT OFFICE.

BERTBAND MONTEIL, OI SOLEURE, SWITZERLAND, ASSIGNOB TO DELTA 00., 0F

. SOLEURE, SWITZERLAND.

' METHOD OF MANUFACTURING ELECTRIC CONTACT PLUGS.

Application filed December 22, 1925, Serial No. 77,145, and inSwitzerland July 31, 1925.

Contact plugs for cylindrical sockets have been knownheretofore havingmale parts formed of a tube the walls of which are separated bylongitudinally extended radial slots into narrow lamellae hangingtogether at their ends. In shaping these plugs the fore ends of themetal shanks were contracted on a press and then the lamellea werebulged out by an axial thrust. Th1s process was employed whether aregulartube was used or whether a solid rod was bored out either part1or on its whole length so as to form a to e before separatmg thelamellae.

The object of the present invention is a process for manufacturingcontact-plugs for c lindrical sockets characterized in that the tickness of the lamellae is determined by a boring extended from the backend unto nearly the fore end of the plug. In this.

way it is possible to produce without any contracting operation, plugshaving lamellae hanging together and having a fore end of any desiredshape, which shape may be 1ven previously on the lathe and be that estsuited for a good contact. The thrustlng operation is eliminated and themechanical operations are greatly simplified and cheapened.

It must be mentioned here, that for currents of greater intensit conicalplugs fitting into conical sockets ave been proposed. In this case withthe view of obtaining a resilient contact both plug and socket were alsoprovided with longitudinally extended radial slots but the diameter ofthe corresponding socket had to be chosenvery exact because if thediameter of the socket dld not fit rather closely a bad contact would bethe result. With plugs according to the present invention however thediameters of the corresponding sockets may vary within certainlimitsw-ithout impairing the contact and therefore such plugs are bettersuited in cases where sockets and plugs are, of different origin.

Therefore and according to the present invention the method ofmanufacturing electrical contact plugs appertaining to cylindicalsockets and having a plurality of resilient arcuated narrow platesseparated by radial slots but still cohering at their'fore ends consistsof forming-the same out of a solid blank by first turning the outside ofFig. 1 is a plug for powerful electric currents.

'This plug has been obtained of solid brass wire. A'fter havin shapedthe outside of the plug on the lathe by giving a predetermined curvingto the contact portions 6 and to the fore-end c and after having madethe thread (i a hole is drilled almost on the whole length of the plugsaid hole beginning at the rear end that is at the socket a andextending close up to the fore end a.

After forming lamellae by means of slots 6, 1n my case six, a prop fhaving the hole 9 for introducing the wires and provided with the threadfor a set screw his forced into the socket end. The plug presentstherefor a hollow space enclosed by the lamellae which are hangingtogether at their both ends. There is no tension whatever in the metalso that the outside shape of a number of plugs is perfectly alike whlchis not'the case with plugs obtained by the. thrust process.

Fig.2 represents a second working form of the plug. The general shape ofthe contact portion that is of the hollow space enclosed by the lamellaeis exactly the same as in Fig; 1. The base of this plug however isthreaded at z' and is screwed into a socket is which is provided with anaxial hole for the wire. Also in this plug the bore on which thethickness and the resilience of the lamelle'e is depending is extendedfrom the rear to the fore end close up to the point 0.-

.The plug represented in Fig. 3 is especially suited for radio plantsand is mostly embedded in radio lamp sockets. The bore as in the firsttwo figures is likewise begun at the base a and extended to the point a.No prop is needed here.

The plug represented in Fig.4 is distinguishied from that in Fig; 3inthat it has a forming the same out of asolid blank by I perforation Z atthe point into which awire first turning the outside of the blank toform may be introduced and soldered fast. same arcuate, then boring anaxial hole up Having thus described my 1nvent1on,'wl iat to an end ofsaid blank for determinin 5 I claim is: thickness of lamellae to beformed and .gnal- {6 In manufacturi g electrical contact plugs 1ycutting longitudinal extending radial appertaining to c llndrica-lsockets and havslots to form lamellae. ing a plurality o resilientarcuated narrow In testimony whereof I aflix my signature. platesseparated by radial slots but still 00- 10 hering at their fore ends,the method of BERTRAND MONTEIL.

